Train 21, the passenger local east, has been sitting at the top of the helix for a long time because South Jackson yard has been full. That makes its movement onto the South Jackson depot siding and eagerly anticipated event. While normally first class train 110 would have been first through Toh Junction and on to the helix, there's another first class train being held up behind No.21 so the passenger train is being permitted through the helix first while waiting for train 110 to finish their block swap.